1. Field of the Invention
The present invention relates generally to a system and method for recording successive images of the same object at varying depths of field. The system takes successive photographs at varying depths of field using a camera and related control method. Multiple photographs of the same object are automatically obtained at varying depths of field within a photographic range of the object when a user takes a photograph using an automatic exposure camera and photographic devices.
2. Description of Related Art
The modern 35 mm camera provides the user with several creative options and controls. As well as composition and camera placement, the user can adjust the lens aperture opening and shutter speed. To obtain a satisfactory photograph, each of these controls must be successfully manipulated.
For example, the lens aperture opening which is often expressed as an F stop number (the ratio of the lens focal length to the lens opening) controls the depth of field of the photograph. The depth of field refers to the depth of the photograph which is acceptably in focus. A photographic lens will only focus on one plane. However, objects spaced close enough to the plane of focus will appear acceptably in focus. Generally, the permissible range around the focused object in which other objects appear to be focused is called "depth of field." The smaller the opening of the lens or the larger the F stop, the greater the depth of field.
As the opening in the lens is decreased to obtain a greater depth of field, however, the shutter speed must be decreased to obtain the same exposure value. A long shutter speed will result in blurring of quickly moving objects and will lead to a greater blur of the overall image in hand-held cameras.
Correct exposure is critical for successful photography. The exposure refers to the amount of light which reaches the image plane and is related to both the F stop and the shutter speed. The smaller the F stop and the longer the shutter speed the greater the amount of light which will reach the image plane. In fully manual cameras, the photographer must manually set both the F stop and the shutter speed. In newer, automatic exposure cameras the camera automatically measures the amount of light and sets the exposure. In programmable cameras, the camera will set both the F stop and the shutter speed.
A conventional automatic exposure camera has multiple exposure programs to obtain various effects. Exemplary exposure programs are an aperture-priority program, a shutter speed-priority program, a deep depth of field program, a rapid shutter speed program and so
In addition, since the impression of the photograph differs according to the degree of exposure, a function is required that the user takes the photograph by adjusting the degree of exposure. Using an auto-bracket program three of photographs having the measured exposure, overexposure, and underexposure can be obtained with only one release.
The photograph is varied to a great deal in accordance with the depth of field, because it is impossible to focus on all the objects to be photographed when composing the photograph. The programs in the automatic exposure camera related to the depth of field are the aperture-priority program and the deep depth of field program. However, there are disadvantages in that the user selects the aperture in the aperture-priority program, and photographs having a deep depth of field are only possible using the deep depth of field program.
Generally, because it is difficult to take a photograph while adjusting the depth of field, there is the disadvantage that an amateur or a beginner may not consistently take acceptable photographs.